In a hydrocarbon plant gas is vented from across the plant and this gas poses a safety hazard. This gas is collected and is burned, in a flare so as to reduce the risk of explosion as well as to ensure that uncombusted gas is not released in the atmosphere. There are available various processes by which this gas can be recovered, but not all the gas vented can be recovered as the quantity or the rate of vented gas is not constant: There is also a possibility of an upset in the plant releasing large amount of gas, often exceeding the recovery capacity installed. Such extra volume of gas available in the confined pipeline increases the pressure of gas making the gas difficult to recover. To avoid the possibility of any mishap the available systems are designed in such a way that a permanent flare is maintained by burning the vented gas. The burning of the vented gas involves substantial costs as this gas is very rich in hydrocarbon content and would have been otherwise recovered. Keeping a permanent flare also solves the problem of sudden and unexpected increase in the volume of vented gas as this gas will also be combusted in the flare.
While the gas at a relatively low pressure can be safely recovered, there is always a risk of the said unexpected increase in pressure making the recovery process difficult and unsafe. Another factor to be considered is to ensure that the recovery of gas does not cause a drop in the pressure of gas in the piping leading to the flare, as it can result in the ingress of atmospheric air into the flaring system creating an explosive mixture in the flare itself; endangering the plant.
An important objective of the present invention is to provide a safe means to allow the recovery of gas, at the same time maintaining utmost safety, and also to prevent the ingress of atmospheric air in the flaring mechanism.
Another important object of the present invention is to provide a seal means capable of breaking instantaneously due to an increase in pressure beyond a predetermined limit, thereby allowing the gas to escape to the flaring mechanism unrestrictedly and being burned safely.
It is a further objective of the present invention to enable total recovery of vented gas thereby reducing the quantity of gas flared to zero during normal operation.
An other important object of the present invention is to provide a means allowing diversion of gas from one flaring system to another flaring system where plurality of flares are used and thereby enabling recovery of gas at a centralized facility.